Our overall objective in the proposed study is to analyze the transretinally recorded complex waves of the vertebrate retina into components, to identify the cell types which generate each component, and to interpret each component in terms of cellular function. Our study will begin by focusing of ERG waves, particularly on the b-, d-, and e-waves which are all vitreal positive potentials and are known to be related to excitatory processes in the retina accompanied by ganglion cell discharge. Applying a combination in intracellular, extracellular, and ion-specific microelectrodes mainly to the frog but also to the mudpuppy and turtle, we will study 1) the relationships between the b-wave and the group of responses within the proximal retina, such as the PNR of Burkhardt, the M-wave of Karwoski and Proenza, the KRG of Oakley, and the Muller cell response of Miller and Dowling, thereby searching for the cellular origin of the b-wave, 2) the same as above but for the d-wave, and 3) also for the e-wave which has been previously studied only by means of a pair of gross electrodes on the opposite sides of the eye. The study will be made with a wide variety of stimulus parameters, such as the size and position of light spot, the light intensity, the duration, the wavelength, and all the above under background light of various intensities. To ease the analysis the ERG current will be controlled by voltage clamp and current clamp techniques, and to minimize stray light, to which the ERG waves are extremely sensitive, optical waveguide fibers will be applied directly on photoreceptors in the retina, which is detached from the pigment epithelium and mounted receptor side up on the indifferent electrode covered by Ringer-soaked black paper tissue.